The team improved upon their previous quadrotor designs that only plucked objects in mid-air while the UAV was hovering. By studying an eagle’s fishing technique, the team noticed how the bird would sweep its legs and claws backwards as its talons gripped its prey. This maneuver allowed the eagle to snatch a meal in one dive-bombing swoop without slowing down.

The team was able to copy the eagle’s technique by 3D-printing a three-fingered claw and attaching it to a four-inch motorized leg. By securing the appendage below the UAV’s center of mass, the drone could grasp stationary objects while flying by.